Merge Audio
Merge Audio joins several audio files into one in your browser, copying the audio without re-encoding when the files match and converting mixed files to MP3 or WAV, so nothing is uploaded.
At a glance
- Accepts
- Two or more M4A, AAC, MP3, WAV, FLAC, OGG or Opus files, in any mix of formats
- Outputs
- One file: the original format when every file matches (lossless), otherwise MP3 or WAV
- Where it runs
- Entirely in your browser, on your device
- What leaves your device
- Nothing - the file never leaves your device
- Limits
- Joins end to end with no gap or crossfade; the result is held in memory until saved
- Account
- Not required - there is no sign-up
- Price
- Free, with no watermark and no usage cap
- Made by
- Visrut
- Last updated
- 12 October 2026
Join several audio files into one: the parts of a recording that got split, a run of voice memos, tracks for a playlist or a podcast episode. Files that share a format and settings are copied back to back without re-encoding, so the result is lossless and ready in a moment. Mixed files are decoded and re-encoded together as one MP3 or WAV. It all runs in your browser.
How to use it
- Drop in two or more audio files, or click to choose them.
- Drag them into the order you want, or use the arrows.
- Pick a format and press Merge, then download the file.
Honest limits
- Files are joined directly, with no gap or crossfade between them.
- A lossless join of M4A files keeps the short lead-in frame each file starts with, which players normally hide, so each join can run about 10 to 20 milliseconds long. There's no click, and it is too short to notice in speech; choose WAV or MP3 if the timing must be exact.
- To cut a part out first, use Trim Audio, then join the pieces here.
Frequently asked questions
Are my files uploaded anywhere?
No. The files are read and joined inside your browser tab with Mediabunny, an open-source media library. Nothing is sent to a server.
Does joining lower the quality?
Not when every file has the same format and settings, such as several voice memos from one phone or parts of one recording. Then Original format is offered: the audio data is copied back to back without being re-encoded, so it sounds exactly like the originals and is ready in a moment. Files that differ are converted to one MP3 or WAV.
Can I mix formats, like an MP3 and an M4A?
Yes. Files in different formats, sample rates or channel counts are decoded and re-encoded together as one MP3 or WAV, at a common sample rate. A mono file in a stereo mix plays in both ears.
How do I change the order?
Drag a file by its handle, or use the up and down arrows. With the keyboard, focus the handle, press Space to pick it up, move it with the arrow keys and press Space again to drop it.
Is there a limit on length or number of files?
No fixed limit. The joined file is held in memory until you save it, so an MP3 of several hours is fine but a WAV that long can be too big for a phone.